Here, There, and Back Again. Incorporating Muscle Oxygenation (SmO2) into Training

13 11 2015

What? It’s been almost a year since my last post. Incredible how time flies by. On the other hand, when you crash hard in a race sometimes it takes awhile to come back.

The outlier crash during the Wenatchee Criterium left me with many facial fractures and wondering if I was ever going to be the same again. Short story version our group was overtaking a lapped racer, some rolled into turn #1 on the inside line, me and some others rolled-in from the outside line. Yeah, I thought there’s plenty of room for us to pass, and we’ll be able to carry our speed through the turn. (This was coasting down from 32 mph – I looked at the Powertap file some days later.) Sure, plenty of room, until…lapped racer guy decides to change his line in the middle of the turn. “No! no! no!” is what I heard my self yelling but it was too late. My front wheel was already overlapped and he was moving out taking us toward the curb. I knew I was going down. The surprise was the steel “No Parking” sign post that materialized right in front of my face. Like it beamed down from the Starship Enterprise. I heard the metallic ping, felt the bouncing-crack of bone all in slow motion. And then there was blackness. That flipping sucked. Worse yet was the two weeks that followed while I had to drink all my meals as my face bones knitted back together. Talk about weight loss. Anyway, that’s over and done with, as is the anger what accompanied it. Next time I’ll move to an inside line early. The 2015 competitive season was a right-off loss after that point.

Anyway, my last post discussed HRV as a means of quantifying recovery. If I recall correctly I didn’t find it fully reflective, that is to say, most of the time I think the method and data were truly representative of my state, but there were other times when I think the estimate was a bit off the mark.

So, on to other things. You may have heard of blood oxygen saturation as a personal, dynamic, physiological indicator of how your particular muscle group(s) is meeting the demand for cycling power? Well, there’s two devices now retail-available by which you can harness this next evolution metric. The first is the MOXY muscle oxygen monitor. A small, portable, go-with-you device that measures the saturation metric (SmO2) at the muscle group of your choice. It will give the SmO2 and blood volume (tHb) metrics so you can get a detailed understanding of what’s happening in your system. The MOXY broadcasts its data via the ANT+ protocol. The other device is the BSX Insight, Generation 2 sensor. Likewise, this instrument measures relative SmO2 and (drum roll) uses an optional protocol to report your lactate threshold in watts and heart rate units. Additionally, this units provides your training zones (based on Dr. Coggan’s percentile structure I believe.) The BSX Insight will accept ANT+ data streams from HR straps and power-measuring devices, and is controlled via Bluetooth from an iPad or Android device. At the moment, The BSX does not broadcast any other devices.

So, for my first move to integrate muscle oxygenation into my training plan, I wrote this short report at the MOXY forum: “First Use of SmO2 during Hypertrophy Training”

“Greetings all,
I hope this is the correct place to post my information and experience using SmO2 to monitor the current lifting phase.

Back squats: Phase 3 of 4 hypertrophy period. Lifting four days/week with a full break on Wednesday. Monday and Thursday are heavy lift days (65, 70, and 75% of one-repetition-maximum -1RM). Tuesday and Friday are light lift days (60, 65, and 70% of 1RM respectively.) Each percentile level consists of two sets of 10 to 12 repetitions each separated by 1.5 to 2 minutes of rest.
Stiff-legged dead lifts: three sets of eight repetitions each separated by 1.5 to 2 minutes rest
51-year-old, male, road-racing since 2009, firm user of periodization plans and quantified, goal-oriented training

Routine: warm-up with 2 minutes of running stairs and no-load squats at the top/bottom of stairwell.

Here’s the results:

P1hwk3 squat sldl.jpg

  1. Starting SmO2 level (~50-70%) appears as expected at the left vastus lateralis location based on other workouts
  2. The recovery baseline was met in all squat lifts except after the second (~8:19:21)
  3. The target, or depletion baseline was met in all squat lift attempts
  4. SmO2 re-stock seems to replenish sufficiently, although the trend slope is steeper/quicker during intervals on the bike trainer comparatively
  5. Stiff-legged dead lifts (SLDL) follow the squats after weight change on the bar
  6. The current weight level of the SLDLs do not seem to produce the same SmO2 depletion rate as the squats before
  7. The SmO2 SLDL re-stock rate seems rather slow compared to the squats rate
  8. Weight bar/rack clean-up occurs after the last SLDL (~8:39)

Monitoring format was based on the guidance from “Moxy Strength Training eBook.” Full recovery was used between lifts as a starting point. Unfortunately, my device does not expose the tHb metric, although the text mentions using this metric as a performance indicator.

Warm-up and bar setup ends at about 8:16. One difficulty was the inability to observe the real-time measure of SmO2 during lifting by use of the Tablet software application. The squat rack is outside and exposed to the weather, which in the current Seattle, Washington weather, would likely render the device unusable. Between-lift breaks are controlled with a stopwatch. I think in order to use the other recovery protocols, I would need to observe the SmO2 measures in real-time, or use appropriate stopwatch durations based on re-stock trends for like workouts.

It’s likely that I didn’t rest long enough after squat #2 in changing weights to the next level (65% 1RM,) hence the insufficient recovery level.


  1. I’m not certain that the depletion target (~43%) meets requirements? Is this target sufficient to cause hypertrophy adaptation? Thoughts?
  2. I think that the SLDLs required their own recovery/target baselines since they are a different lift pattern. Thoughts?

I think I’m generally on the right track in order to achieve the plan intent and outcomes. My plan is similar to last year’s; and contains corrections for lessons-learned. Your comments and thoughts are welcome! Thanks for reading.”

There will be more posts with SmO2 content to follow. Specifically, reports concerning the determination of training zones based on individual physiological markers like SmO2 and tHb, and improving the quality of focused training like intervals. Stay tuned and thanks for reading!

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